Vertical alignment of a rifle scope with the bore of a rifle it is mounted on is often somewhat of a hit or miss exercise. Rifle sighting scopes are typically mounted atop a rifle barrel via clamping rings which are tightened via screws provided on either side of each clamping ring. Preferably, the clamping rings are aligned on the rifle barrel such that, when the scope is attached, the crosshair formed by the intersection of the horizontal and vertical scope reticles is reasonably well aligned with the barrel bore. Thus, the scope, once adjusted for windage and elevation, is accurate in the center of the reticle. However, the scope is not necessarily aligned vertically with the rifle barrel bore.
A problem arises during long distance shooting where a shooter must adjust the angle of his shot to account for the drop of the bullet during its trajectory to the target. In order to compensate for this drop, the shooter will typically move the rifle upward, i.e. move the target image vertically downward along the vertical reticle within the scope. However, if the scope is aligned with the rifle bore only at the center or crosshair of the horizontal and vertical scope reticles, i.e. the scope is misaligned vertically, which is often the case, as the target image is moved away from the crosshair along the vertical reticle, a horizontal error will be introduced.
It is clear, then, that a need exists for a simple and reliable apparatus and method for vertically aligning a rifle scope with the bore of a rifle upon which the scope is mounted.